Railroad gangs were brought in for building new track and for repairing old track during the good weather , which usually meant anytime after the frost left the ground until it returned in late October. This was hard work at the best of times but it was miserable work in Northern Ontario.
May to June ...blackfly season . Blackflies rose from the high waters of spring melt and choked anyone outside , entering every oriface one could think possible . Every landing meant a piece of flesh disappeared . The warm , sweating bodies of gangs and section men alike were easier to bite . Their faces would be swollen from hundreds of bites . Eyes , ears and hairlines bloodied by their pursuors . As long as it was daylight , there were blackflies . As long as a person was outside , there was a cloud of them contantly in motion around the head , relentless in their pursuit of flesh .